Synthesis and characterization of a crosslinked chitosan derivative with a complexing agent and its adsorption studies toward metal(II) ions

Removal of cadmium from aqueous solution using low molecular weight chitosan derivative

“…It was observed that as pH of the solution increases from 6 to 10 at both low and high levels of temperature (B) and Cd(II) concentration (C), the removal efficiency decreased by 24% and 5.7%, respectively. At the alkaline pH, the auxiliary complexation agents from the buffer can form complexes with the metal ion in order to avoid precipitation of the metal hydroxide which lowers the sorption of the metal ion by the sorbent (Justi et al, 2005;Krishnapriya & Kandaswamy, 2009).…”

“…For each run, weighted amount of cross-linked low molecular weight chitosan pyruvic acid derivative (0.05 g) was added to the flask containing 25 mL of Cd(II) concentration (1 or 3 mg/L) of desired pH (6 or 10) (potassium hydrogen phosphate/NaOH or sodium bicarbonate/NaOH buffer solution, respectively). The buffer solutions were used to adjust the pH and as auxiliary complexing agents to prevent precipitation of cadmium salt at alkaline pH (Justi, Fávere, Laranjeira, Neves, & Peralta, 2005;Krishnapriya & Kandaswamy, 2009). The solution was agitated at 200 rpm for 4 h at the required temperature (45 or 70 • C).…”

Chitosan/siloxane hybrid polymer: synthesis, characterization and performance as a support for immobilizing enzyme

“…15 This macromolecule, derived chemically by deacetylation of chitin, the second most abundant biopolymer in nature close to cellulose, has widely been assumed to be a cheaper and versatile sorbent for transition metal ions and organic substances through the coordination and/or reaction sites composed of the amino (-NH 2 ) and hydroxy (-OH) groups anchoring on chitosan chains. 20 As a matter of fact silica-chitosan possesses a highly porous microstructure and has been shown to be a superior support for immobilizing enzymes. 1 Moreover, it is inexpensive, non-toxic, hydrophilic, biocompatible and biodegradable.…”

Effects of chitosan membrane morphology on copper ion adsorption

“…The dependence of background electrolyte concentration and counter ions present in solution on zeta potential is well known. It can be assumed that a high concentration of SO 4 2− in the electrolyte causes adsorption of these anions by polymer and decreases the positive value of the . Consequently, chitosan possesses a negatively charged character- istic and shows additional ability to increase its uptake capacity to Cu 2+ (electrostatic mechanism) [34].…”

“…The soil surrounding these sites is also polluted and can contaminate groundwater and surface water. Heavy metals are not biodegradable and tend to accumulate in living organisms, causing various diseases and disorders [1][2][3][4]. Copper pollution is of particular concern.…”